On Sep 24, 14:24, Joe wrote: from. for the number but didn't find anything. I found these drives in the same pile with some IBM RS/6000 cards. Does anyone know if the RS/6000 uses anything like this? I'd never heard of a 5.25" 2.4MB floppy before this, but I know that some models of the RS/6000 range and I believe also some PS/2 range had so-called "2.88MB" 3.5" floppies. I have one here (the drive,that is, not the RS/6000). They look just like ordinary 3.5" HD floppies except for the extra media sensor. They can use normal DD or HD disks, or special ED disks which have the media sensor hole in a different place to HD disks -- it's slightly further from the bottom edge, so if you put an ED disk in an HD drive, it would be seen as DD. However, the coating is a special barium ferrite rather than the normal cobalt ferrite, and for ED, the drive uses a vertical recording technique developed by Toshiba instead of normal longitudinal recording. If the disk in the drive you've found looks just like a normal HD floppy, that's what it is -- not an Extra Density one. Apart from IBMs they were also used in 3Com Netbuilder routers. -- Pete Peter Turnbull Network Manager University of York